TY JOUR TI WAYS OF IMPROVING THE DETECTION OF IMPACTS EMERGENCY BY UNMANNED AERIAL VEHICLES KW unmanned aerial vehicle KW chemically hazardous substance KW drone-kvadrokopter JO Problems of risk management in the technosphere AU Savchuk, O.N. AU Silnikov, M.V. PY 2017 IS 2017 PB Saint-Petersburg University of State Fire Service of Emercom of Russia